Electromagnetically operated valve - has cylindrical magnetostrictive actuator which contracts in axial magnetic field of selectively energised windings to allow fluid flow between adjacent ports

摘要

The cylinder (102) of magnetostrictive material almost completely fills the bore (101) in which it is sealed with O-rings (120-122) and urged towards one end by a stack of spring washers (103). Five fluid connections (107-111) opening into respective annular grooves (112-116) in the wall of the bore (101) are interconnected as required by selective excitation of coils (117-119) generating the axial magnetic field which causes local deformation of the cylinder (102), opening corresp. passages (104-106) between grooves (112-116). A longer cylinder may be divided axially into sections sepd. by spring washers. ADVANTAGE - Any number of valve passages can be controlled independently.